The present invention relates to a technology for producing semiconductor devices and, particularly, to a semiconductor device equipped with a resin-sealed package of surface mount type, such as one which has many pins and a small heat resistance, and is small in size and is produced at a decreased cost.
As ICs are now produced having many functions, and are highly densely fabricated and operate at high speeds, it has been desired to develop a surface mount resin-sealed package having many lead pins with a good heat-emitting property or a small heat resistance. A surface mount type resin-sealed package which is constituted as described below has been proposed in, for example, Japanese Patent Laid-Open No. 286558/1991.
In such a package, the tabs to which a semiconductor pellet is bonded and heat-radiating fin leads are integrally formed together, and the heat-radiating fin leads and heat-radiating fins outwardly protruding from a sealing resin member of the package are integrally formed together. Moreover, a heat sink is buried in the package on the side of the back surface of the tabs, and is mechanically coupled to the heat-radiating fin leads inside the package.
A QFP (quad flat package) which has a good heat-radiating property and whose outer leads are prevented from deforming has been disclosed in Japanese Patent Laid-Open No. 218262/1993.
This QFP employs a lead frame and tabs to which a semiconductor pellet is bonded and heat-radiating fin leads are formed integrally. The heat-radiating fin leads and heat-radiating fins outwardly protruding from the sealing resin member of the package are integrally formed, the tips of the heat-radiating fins being outwardly protruded beyond the tips of the outer leads.